Evolved UMTS Terrestrial Radio Access (E-UTRA) protocol, also referred to as Long-Term Evolution (LTE), is a wireless communication protocol specified by the Third Generation Partnership Project (3GPP). Advanced versions of the LTE are referred to as LTE-Advanced (LTE-A). As part of the IP Multimedia Subsystem (IMS) architecture used in LTE and LTE-A, several protocols have been developed for transferring voice calls over LTE networks. These protocols are referred to as Voice over LTE (VoLTE). VoLTE is specified, for example, in Permanent Reference Document (PRD) IR.92 of the GSM Association (GSMA), entitled “IMS Profile for Voice and SMS,” version 7.0, Mar. 3, 2013, which is incorporated herein by reference.